Sewing-machine



@NRM/Lemay (No Model.) 2 Sheets-Sheet 1f A.. M. LESLIE.v SEWING MACHINE.

No. 444,758. Patented Jan. 13,- 1891.

gnou/4oz ARTHUR M. Lis/Jr,

(No Model.)

2 Sheets-Sheet 2. A. Mr LESLIE. SEWING MACHINE.

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ARTHUR M. LESLIE, OF EVANSTON, ILLINOIS.

SEWING-MACt-HNE.

SPECIFICATION forming part of Letters Patent No. 444,758, dated January 13, 1891.

Original appieatiou iiled November 14, 1887, Serial No. 255,153. Divided and this application tiled July 30, 1889. Renewed July i 11,1890. SerialNo. 358,417. (No model.)

To all zu/"tom, t may conoci-7L.-

Be it known that I, ARTHUR M. LESLIE, a citizen ot' the United States, and a resident of Evanston, in the State of Illinois, having my place of business at Chicago, in said State, have invented a new and useful Improvement in Mechanical Movements for Sewing-Machines, of which the Vfollowing is a speciiication. t

The primary object of this invention is to increase the adaptation of rotary-sh uttle sewing-machines to work noiselcssly and with as little friction as possible at the high speeds which their continuous rotary motion renders The invention is applicable, however, wholly or in part to other sewing-machines.

The presentinvention consists, lirst, in a novel and peculiarly frictionless and com pact link-motion struct-ure employed in common to guide a vertically-moving fulcrum for a lever-pitm an transmitting rotary motion from a shaft in the overhan ging arm to the shuttle driving shaft below the bed-plate and to guide a vertically-moving needlebar, and, seeondly, in a peculiar combination of such linkmotion guides for a reciprocating needle-bar, whereby lubricating the latter to the usual troublesome extent is obviated.

Two sheets of drawings accompany this specification as part thereof.

Figure 1 of these drawings represents an elevation of a sewing-machine heath or machine proper, partly in longitudinal section, illustrating the present invention. Fig. 2 represents a vertical section on the lino 2 2, Fig. l, showing the said lever-pitman with its fulcrum in clevat ion. Fig. 3 represents a scctional plan ofthe latter viewed from the liuc 3 3, Fig. 2. Figs. 2X and 3X are fragmentary sectional views corresponding, respectively, with Figs. 2 and 3 as to plane and illustrating a modilication. Fig. t represents a vertical section on the line 4 i, Fig. l; and Fig. 5 represents a horizontal section on the line 5 5, Fig. et.

Like letters of reference indicate corresponding parts in the several iigures.

The machine may have an arm A, bed-plate 13, and cloth-plate C, of any approved design, suitably united with each other. Preferably the arm is hollow, as shown, so as to inclose a rotary upper shaft S and the mechanism which transmits motion therefrom to a parallel rotary shaft S2 below the bed-plate, said upper shaft being provided at its right-hand end with a pulley P and hand-wheel IV, Fig. l, as the driving-shaft.' Said transmitting mechauism consists of a crank C', integral with the shaft S', in line with the upright portion or standard of the arm, a lever-pitman L within said standard coupled to said. crank, a peculiar link-motion fulcrum F for said pitman, and a suitable crank C2 on the right-hand end of said under shaft S2, to which the lower end of the pitman is coupled. As shown by Figs. 2 and 3 in connect-ion with Fig. 1, said fulcrum F consists of an L-shaped primary link a, supported at the extremities of one member by axial pivot-screws a a2, Fig. l, a substantially horizontal link b, pivoted at one end to the pitman and to the extremity of the swinging member of said link d behind the pitman, and having a horizontally-yielding pivot b at its rear end, and in one arrangement a vertical link c, supporting said yielding pivot at its upper end and pivoted at its lower end at the bottom of the standard. All the pivots are parallel with the wrists of the cranks C C2, and, excepting said pivots a ai, all may be formed by shouldered screws, as shown in Fig. As illustrated by Figs. 2X and 3X, said yielding pivot b may, in an altern ative form, be integral with said link b and supported by a fixed projection c2 within the arm-standard, havin g a suitable horizontal rccess. The operation ot the fulcrum is illustrated by full and dotted lines in Fig. 2, showing the parts in two positions, andv by arrows indicating the rotation of the respective shafts It will be seen that the pivotal centerof the pitman moves straight up and down, thus relieving the motion from the varying effect produced by the shifting of the pitman center back and forth when a single radiuslink is used, and at the same time the friction is materially reduced, as compa-red with a sliding connection. At its left-hand end said arm A is rigidly united with the customary head II, and said upper shaft S carries a combined take-up cam and needle-driving crank C3, which, together with IOO ordinary cfmnections, oseillatcs a take-up lever T, that .projects through the face-platel of the head and reci procates a needle-bar N, that carries at its lower end a straight-eye pointed needle. The needle-bar is guided by peculiar means forming part of the present invention as illustrated by Figs. 4f and 5 in connection with Fig. l-that is to say, a pair of link-motion guides G, Figs. 4 and 5, substantially similar to said link* motion fulerum F, coacting with each other, form a parallel-n'iotiou device which supports and guides the needle-bar, so that the customary drilled guides, with their glands and other accessories, are dispensed with and lubricating the needle-bar is reduced to a minimum. The shift-ing pivots b of these guides are preferably spherical, and work in thimbles c3, which are screwed into the rear edge of the head. yOtherwise the guides G,as shown, are identical with said fulcrum F, except as to size, and 'need not therefore loe more particularly described.

T2, :F.ig. 1,1epresents the upper tension device yof the machine; t, the upper threadguides; 3the spool of upper thread; s,its spindlegP the presser; D, the shuttle-driver disk; Cil, a ixed cam auxiliary to theshuttledriver; R, thefshuttle-race; S2, a disk shuttle Within the latter; b2, the bobbifn-case; Ff, the feed-bar; f, its dog, and@5 Cirs cams. These parts,ltoget'her with the remainderot' thesewing mechanism proper, form no kkpart of my present invention.

The .peculiar shuttle-cam, shuttle-driver, and shuttle-race represented in Fig. lconstitute the subject-matter .of my specification forming `:part of an application for patent,

'to specified details, except as therein stated.

l Iaving'thus described the said mechanical movements and a machine embodying the same, l claim as my invention and desire to patent under this Specification- 1. In combination with a moving part, a link-motion structure to support and guide the same, composed of a link substantially of -L shape, axial pivots at the extremities of one member thereof, a link pivoted tothe said moving part at one end and having'a laterally-yielding'pivot at its other extremity and pivoted at an intermediate point to the other mem ber of the lin'k first named,and supports for said axial pivots and `said laterally-yielding pivot, substantially as hereinbefore specified.

2. In combination with Vthe needle-bar .of a sewing-machine, a pair of link-motion guides, each composed of a link substantially of EL shape, axial Ypivots at the extremities ofone member thereof, a link pizvoted to the .zneedlebar at .one-end and having a `laterally-yield ingpivot-at its other extremity and pivoted at an intermediate point to the other member of the link first named, and supports for said axial pivots vand said laterally-yielding pivot, substantially as hereinbefore specified.

A. M. LESLIE. N'Vitnesses:

MAX L. LIVINGSTON, CHAS. W. CHANDLER. 

